Sulfonylhydrazide phosphonates

ABSTRACT

PHOSPHORUS-CONTAINING SULFONYLHYDRAZIDES OF THE FORMULA:   (R1,(H2N-NH-O2S-)PHENYL)-CH2-P(=O)(-O-R)2   IN ADDITION CHLOROSULFONATED PHOSPHORUS-CONTAINING COMPOUNDS USEFUL AS ORGANIC INTERMEDIATES IN THE PREPARATION OF THE HYDRAZIDES ARE DESCRIBED. THE PHOSPHORUSCONTAINING SULFONYLZIDES ARE DESCRIBED. THE PHOSPHORUSCONTAINING SULFONYL-HYDRAZIDES ARE USEFUL AS BLOWING AGENTS FOR RESINOUS BLENDS.

United States Patent 3,658,951 SULFONYLHYDRAZIDE PHOSPHONATES John E.Herweh, Lancaster, Pa., assignor to Armstrong Cork Company, Lancaster,Pa.

No Drawing. Filed Aug. 5, 1969, Ser. No. 847,715 Int. Cl. C07f 9/40 US.Cl. 260--923 3 Claims ABSTRACT OF THE DISCLOSURE Phosphorus-containingsulfonylhydrazides of the formula:

3 2% -fi a In addition chlorosulfonated phosphorus-containing compoundsuseful as organic intermediates in the preparation of the hydrazides aredescribed. The phosphoruscontaining sulfonyl-hydrazides are useful asblowing agents for resinous blends.

BACKGROUND OF THE INVENTION Field of the invention The invention relatesto phosphorus-containing sulfonylhydrazides useful as blowing agents.

Description of the prior art Sulfonylhydrazides have been found usefulas blowing agents and a class of phosphorus-containingsulfonylhydrazides is disclosed in Herweh et al. US. Patent 3,423,485.

BRIEF SUMMARY OF THE INVENTION This invention relates to a novel classof compounds represented by the formula:

I (sch-Ffl DESCRIPTION OF THE PREFERRED EMBODIMENTS Dialkylbenzylphosphonates of the formula:

l I (M r-La d are reacted with chlorosulfonic acid to form thechlorosulfonated derivative and this is reacted with hydrazine to formthe hydrazide.

In the formula R may be lower alkyl such as methyl and ethyl and R maybe halogen, N0 lower alkyl such as methyl and ethyl, and H. Examples ofdialkyl benzylphosphonates useful as starting reactants are dimethylbenzylphosphonate, diethyl benzylphosphonate and substituted dialkylbenzylphosphonates such as dimethyl Patented Apr. 25, 1972(methylphenyl) methylene phosphonate, diethyl (nitrophenyl) methylenephosphonate, and dimethyl (chlorophenyl) methylene phosphonate.

The compounds of this invention are formed by initiallychlorosulfonating dialkyl benzylphosphonates or substituted dialkylbenzylphosphonates by adding the phosphonate to excess chlorosulfonicacid at room temperature. The crude chlorosulfonated phosphonates areobtained as chloroform soluble oils upon quenching the reaction mixtureby addition to a mixture of ice and an organic solvent such aschloroform.

The chlorosulfonated derivatives are then reacted with hydrazine byadding hydrazine to a solution of the chlorosulfonated phosphorus esterin a polar solvent such as tetrahydrofuran or acetonitrile. The additionis made with stirring at low temperature 0i5 C. and, upon completion ofthe addition, the stirred solution is allowed to warm to roomtemperature. Usually a 5% to 10% molar excess of hydrazine is employed,two moles of hydrazine per mole of sulfonyl chloride being required tocomplete the reaction.

EXAMPLE 1 Preparation of dimethyl p-chlorosulfonylbenzylphosphonateDimethyl benzylphosphonate (40 grams 0.2 mole) was added dropwise inhour to stirred chlorosulfonic acid,

EXAMPLE 2 Preparation of dimethyl p-hydrazidosulfonylbenzylphosphonateTo the crude chlorosulfonated dimethyl benzylphosphonate of Example 1(24 grams 0.08 mole) in ml. of tetrahydrofuran was added in 20 minuteswith stirring 85% hydrazine (7 grams, 0.186 mole). Reaction temperatureswere maintained at 0 15 C. during the addition. The two phase reactionmixture (clear, colorless solvent layer and white solid) was stirred at0 C. for 2 hours and left to warm to room temperature. The white solidprecipitate was filtered and washed consecutively with freshtetrahydrofuran and ether. The dried filtercake (23.8 grams) was washedwith cold water to remove hydrazine hydrochloride; the aqueous insolublewhite solid (16.6 grams after drying) melted at 132 C. withdecomposition.

The tetrahydrofuran filtrate was distilled under reduced pressure andleft 4 grams of additional product. The combined crops of crude product(20.6 grams) recrystallized several times, gave a whitesulfonylhydrazide (M.P. 142- 144 dec.).

Analysis.Calculated for C H N O PS (percent): C, 36.7; H, 5.1; N, 9.5;P, 10.5; S, 10.9. Found (percent): C, 36.9; H, 5.2; N, 9.4; P, 10.5; S,10.9.

EXAMPLE 3 Preparation of diethyl p-chlorosulfonylbenzylphosphonatechlorosulfonic acid (349.5 grams, 3.0 mole) and diethylbenzylphosphonate (68.5 grams, 0.3 mole) were reacted in accordance withthe procedure of Example 1. Workup of the reaction mixture in accordancewith the 3 procedure of Example 1 gave 80.7 grams (82%) of the crudechlorosulphonated' product.

EXAMPLE 4 Preparation of diethyl p-hydrazidosulfonylbenzylphosphonateAqueous 85% hydrazine (7.2 grams, 0.19 mole) was added dropwise in 20minutes with stirring to a solution of crude chlorosulfonated diethylbenzylphosphonate (29.5 grams, 0.09 mole) in 100 milliliters oftetrahydrofuran maintained at --5 to C. Upon completing the addition,the reaction mixture was worked up in accordance with the procedure ofExample 2. Hydrazine sulfate (9.3 grams) and crude sulfonylhydrazide(18.4 grams, M.P. 126 to 128 C. dec.) were obtained. Tworecrystallizations of the crude sulfonylhydrazide from absolute ethylalcohol raised the melting point to 130.5 to 132 C. with decomposition.

Analysis.Calculated for C H N O PS (percent): C, 41.0; H, 5.9; N, 8.7;P, 9.0; S, 10.0. Found (percent): C, 40.9; H, 6.1; N, 8.9; P, 9.9; S,10.0.

Sulfonylhydrazides prepared from the chlorosulfonated dialkylbenzylphosphonates are useful as blowing agents for resinous blends.Thermal decomposition (Table I) of the sulfonylhydrazides yieldsnitrogen, water and phosphorus-containing residue. The latter mayfunction as a fire retardant in the resulting foamed plastic.

TABLE I.THERMAL DECOMPOSITION OF SULFONYLHY- DRAZIDES IN NUJOL Ml. ofgas per 111 mole Dec. of sulfonyl- Gas temp., hydrazide at yield, R: C.infinite time percent CH 129. 5 16. 3 73 CHaCHz 129. 5 21. 2 95 EXAMPLE5 Free-flowing particles (dry blend) of plasticized thermoplastic vinylresin were formed by mixing a masterbatch of the following compositionin a Henschel Blender at a temperature below about 200 F.

The master-batch was prepared by blending the ingredients in a smallHenschel Mixer. Initially the pigment was added to the polyvinylchloride homopolymer and the mixture was blended at a slow speed for oneminute.

Following this one half of the dioctyl phthalate and all of theepoxidized soybean oil was added and blended at high speed until thetemperature of the mix reached 165 F. At this temperature, the remainingdioctyl phthalate and all of the stabilizer were added and blending wascontinued until the temperature reached 175' F. At 175 F. 3% by weight,based on the Weight of the formulation, of dimethylp-hydrazidosulfonylbenzylphosphonate was added and the mix blended at aslow speed until a temperature of 200 F. was attained. The mix was thencooled to F. by addition of Dry Ice at slow speeds and finally thecalcium silicate was added and blended and blending continued for of aminute.

Using a portion of the dry blend, prepared as described above, the dryblend was laid up to a thickness of mils on a rubber bonded asbestosrfi-ber felt 0.039 inch thick. The sample thus prepared was then placedbetween two heated platens and held for 60 seconds after which the fusedsheet that formed was cooled and stripped from the felt and examined.During fusion the top platen was maintained at a temperature of 1020 F.and the bottom platen was maintained at a temperature of 420 F.

The foam polyvinyl chloride resin sheet thus prepared had an averagedensity of 23.3 pounds per cubic foot and had a rough surface with acoarse texture.

The preferred percentage range for blowing agents is between about 1% to5% by weight, based on the organic resin component.

I claim:

1. The compound of the formula:

3 ozNz s R LE 3,423,485 1/1969 Herweh et a1. 260923 JOSEPH REBOLD,Primary Examiner R. L. RAYMOND, Assistant Examiner US. Cl. X.R.

